RFC 959 *requires* to implemet a portion of the telnet
protocol in the command channel. Without this ftlib has
problems interacting with RFC959-compliant server (most
Unix ftp daemons are compliant) if, e.g., a directory
or a filename contains russian characters.

The attched patch implements a minimal requirement (it
doubles chr(255) in the .putline() method), but it
allows a programer to choose if a session will be
strict or not. Default value is "not strict" because
most clients (even Unix clients) do not implemet this
telnet option, and most Windoze servers do not implemet it.

Tested with ProFTPd on GNU/Linux system.